The
Oilbird (
Steatornis caripensis), also known as
Guácharo, is a slim, long-winged bird related to the
nightjarNightjars are medium-sized nocturnal or crepuscular birds with long wings, short legs and very short bills. They are sometimes referred to as goatsuckers from the mistaken belief that they suck milk from goats . Some New World species are named as nighthawks...
s and usually placed with these in the
orderIn scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
CaprimulgiformesThe Caprimulgiformes is an order of birds that includes a number of birds with global distribution . They are generally insectivorous and nocturnal...
. It is sufficiently distinctive to be placed in a family (
Steatornithidae) and suborder (
Steatornithes) of its own; more recent research indicates that it should even be considered a distinct order (which does not yet have a valid taxonomic name).
The
Oilbird (
Steatornis caripensis), also known as
Guácharo, is a slim, long-winged bird related to the
nightjarNightjars are medium-sized nocturnal or crepuscular birds with long wings, short legs and very short bills. They are sometimes referred to as goatsuckers from the mistaken belief that they suck milk from goats . Some New World species are named as nighthawks...
s and usually placed with these in the
orderIn scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
CaprimulgiformesThe Caprimulgiformes is an order of birds that includes a number of birds with global distribution . They are generally insectivorous and nocturnal...
. It is sufficiently distinctive to be placed in a family (
Steatornithidae) and suborder (
Steatornithes) of its own; more recent research indicates that it should even be considered a distinct order (which does not yet have a valid taxonomic name). It is found in the northern areas of
South AmericaSouth America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere...
from
GuyanaGuyana officially the Co-operative Republic of Guyana and previously known as British Guiana, is a state on the northern coast of South America that is culturally part of the Anglophone Caribbean.Guyana was discovered in 1498 by the Europeans,Guyana's past is punctuated by battles fought and won,...
and the island of
TrinidadTrinidad is the larger and more populous of the two major islands and numerous landforms which make up the country of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just 11 km off the northeastern coast of Venezuela. With an area of 4,768 km² it is also the fifth...
to
VenezuelaVenezuela , officially titled Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It is a continental mainland with numerous islands located off its coastline in the Caribbean Sea...
,
ColombiaColombia , officially the Republic of Colombia , is a constitutional republic in northwestern South America. Colombia is bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the northwest by Panama; and to the west by the Pacific Ocean...
,
EcuadorEcuador , officially the Republic of Ecuador , literally, "Republic of the equator") is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America that...
,
PeruPeru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean.Peruvian territory was home to the Norte Chico...
and
BoliviaBolivia, officially Plurinational State of Bolivia , is a landlocked country in central South America. It is bordered by Brazil to the north and east, Paraguay and Argentina to the south, and Chile and Peru to the west....
in forests and woodland with caves. It is a seasonal
migrantBird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. These however are usually irregular or in only one direction and are termed variously as nomadism, invasions,...
, moving from its breeding caves in search of fruit trees. It has occurred as a rare vagrant to
Costa RicaCosta Rica, officially the Republic of Costa Rica is a country in Central America, bordered by Nicaragua to the north, Panama to the east and south, the Pacific Ocean to the west and south and the Caribbean Sea to the east.Costa Rica, which translates literally as "Rich Coast", constitutionally...
,
PanamaPanama, officially the Republic of Panama , is the southernmost country of both Central America and, in turn, North America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the...
and
ArubaAruba is a -long island of the Lesser Antilles in the southern Caribbean Sea, north of the Paraguaná Peninsula, Falcón State, Venezuela. Together with Bonaire and Curaçao, it forms a group referred to as the ABC islands of the Leeward Antilles, the southern island chain of the Lesser Antilles.An...
.
This nocturnal species, uniquely, is a specialist feeder on the fruit of the
Oil PalmThe oil palms comprise two species of the Arecaceae, or palm family. They are used in commercial agriculture in the production of palm oil. The African Oil Palm Elaeis guineensis is native to west Africa, occurring between Angola and Gambia, while the American Oil Palm Elaeis oleifera is native to...
and tropical
laurelThe Lauraceae or Laurel family comprises a group of flowering plants included in the order Laurales. The family contains about 55 genera and over 2000 species world-wide, mostly from warm or tropical regions, especially Southeast Asia and Brazil...
s. All the other nightjars and their relatives are
insectivoreAn insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures.Although individually small, insects exist in enormous numbers and make up a very large part of the animal biomass in almost all non-marine environments...
s.
The Oilbird's feet are small and almost useless, other than for clinging to vertical surfaces. However, it is capable of hovering and twisting flight, which enables it to navigate through restricted areas of its caves.
This is a large bird at 41-48 cm (16-19"), with a wing span of 91 cm (3 ft). It has a flattened, powerfully hooked bill surrounded by deep chestnut rictal bristles up to 5 cm (2") long. It is mainly reddish-brown with white spots on the nape and wings. Lower parts are cinnamon-buff spotted with white. The stiff tail feathers are a rich brown spotted with white on either side.
During the day these gregarious birds rest on cave ledges. The nest is a heap of droppings, usually above water - either a stream or the sea, on which 2-4 glossy white eggs are laid which soon become stained brown. These are rounded but with a distinctly pointed smaller end and average 41.2 X 33.2 mm.
The squabs become very fat before fledging, weighing up to half again as much as the adult birds do. They used to be harvested and rendered for oil, whence the name "oilbird".
Although the Oilbird forages by sight, it is one of only a few birds, and the only nocturnal one, known to navigate by
echolocationEcholocation, also called biosonar, is the biological sonar used by several animals such as dolphins, shrews, most bats, and most whales. The term was coined by Donald Griffin, who was the first to conclusively demonstrate its existence in bats...
in sufficiently poor light conditions, using a series of sharp audible clicks for this purpose. It also produces a variety of harsh screams while in its caves. Entering a cave with a light especially provokes these raucous calls; they also may be heard as the birds prepare to emerge from a cave at dusk.
The oilbird is called a "guácharo" or "tayo" in
SpanishSpanish or Castilian is a Romance language in the Ibero-Romance group that originated in northern Spain and gradually spread in the Kingdom of Castile, evolving into the principal language of government and trade in the Iberian peninsula...
, both terms being of indigenous origin. In Trinidad it was sometimes called "diablotin" (French for "little devil"), presumably referring to its loud cries, which have been likened to those of tortured men.
The
Guácharo CaveThe Guácharo Cave National Park , located 12 km from the town of Caripe, has as its centerpiece a large limestone cave, which is home to thousands of oilbirds...
(Oilbird Cave), in the mountainous
CaripeCaripe is the name of a town and municipality in the mountainous north of the state of Monagas in eastern Venezuela.The soil of the Caripe valley is very fertile, and the climate of the area is exceptionally pleasant, a result of its altitude , latitude , and proximity to the Caribbean Sea...
district of northern
MonagasEstado Monagas is one of the 23 states into which Venezuela is divided.Monagas State covers a total surface area of 28,900 km² and, in 2007, had an estimated population of 855,300....
,
VenezuelaVenezuela , officially titled Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It is a continental mainland with numerous islands located off its coastline in the Caribbean Sea...
, is where
Alexander von Humboldtwas a German naturalist and explorer, and the younger brother of the Prussian minister, philosopher, and linguist, Wilhelm von Humboldt...
first studied the species. The
caripensis of the binomial name means "of Caripe", and
Steatornis means "fat bird", in reference to the fatness of the squabs.
The Guácharo Cave was Venezuela's first national monument, and is the centerpiece of a national park; according to some estimates there may be 15,000 or more birds living there.
ColombiaColombia , officially the Republic of Colombia , is a constitutional republic in northwestern South America. Colombia is bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the northwest by Panama; and to the west by the Pacific Ocean...
also has a national park named after its "
Cueva de los GuácharosThe Cueva de los Guácharos National Park , created in 1960, is the oldest of the 51 protected areas of Colombia. The park is located in the western face of the Colombian Eastern Andean Range in the departments of Huila and Caquetá...
", near the southern border with Ecuador. Oilbirds have been reported in various other places along the
AndeanThe Andes are the world's longest exposed mountain range. They lie as a continuous chain of highland along the western coast of South America...
mountain chain, including near Ecuador's
Cueva de los TayosCueva de los Tayos is a natural cave located on the eastern slopes of the Andes mountains in the Morona-Santiago province of Ecuador...
and in
BrazilBrazil , officially the Federative Republic of Brazil , is a country in South America. It is the fifth largest country by geographical area, occupying nearly half of South America, the fifth most populous country, and the fourth most populous democracy in the world. Bounded by the Atlantic Ocean...
: they are known to dwell as far south as the Carrasco National Park in
BoliviaBolivia, officially Plurinational State of Bolivia , is a landlocked country in central South America. It is bordered by Brazil to the north and east, Paraguay and Argentina to the south, and Chile and Peru to the west....
. Dunstan Cave, at the
Asa Wright Nature CentreThe Asa Wright Nature Centre and Lodge consists of a nature resort and scientific research station located in the Arima Valley of the Northern Range in Trinidad and Tobago. The Centre is one of the top birdwatching spots in the Caribbean; a total of 159 species of birds have been recorded there...
in
TrinidadTrinidad is the larger and more populous of the two major islands and numerous landforms which make up the country of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just 11 km off the northeastern coast of Venezuela. With an area of 4,768 km² it is also the fifth...
, is home to about 200 nesting pairs of oilbirds.
External links